I know there are multiple factors here so nothing is exact and the answer many times is "it depends".  However, I'm looking for a starting point for a bow.

Bow is an ILF 35# @28" drawn to 28".  Using Big Jim Dark Timber shafts.  I've shot the 800's with 125, 150, 175 grain heads with the arrow as short as I can go.  All showing weak, but the 125 grain head is close. 

I know I need to go up in arrow spine.  However, if you were going to use this bow to hunt, what weight point would you start with?  I like simmons sharks and have 135, 165, and 175 grain heads.  I was leaning toward 175 grain because I have more of them.  But doesn't have to be that weight.

Past while now,  I usually lean towards not throwing my 2 cents in with regards to tuning for the mere fact that there are so so many variables,  one of them being the variable of "subjective" (things like form issues,  draw lengths that are not accurately measured, those sorts of things).  That being said,  I'm going to tell you that this is something you are going to have to figure out by your lonesome.... and I wont say unfortunately,  it's just the way it goes and it's a good thing.  You need to tinker and shoot,  and repeat. And repeat! And again!  If your form is still evolving,  and this happens very often,  you may notice what you thought worked before,  can actually be improved on (talking specifically about arrow tuning/flight here) or might not work that great at all.  And it all comes from shooting these different recipes A LOT!  Get a field point test set.  Bare shaft your carbons with different weights with the goal of picking a spine that will jive with a particular broadhead design (and weight) that you have in your head that you'd like to shoot.  You will see what will do the trick and what will not.  Then,  start tinkering with your broadheads with fletched carbons.  Some of the longer heads, well they just might effect your spine .... keep this in mind.   Trial and error with this.  Does require a little work, but a great learning process and once you know,  you know ..... what works ok,  what works best,  and what doesn't work at all. Last thing I'll say here,  do not settle for broadhead flight that is close to what your field points show on a target.  There is no reason you can't have your broadheads fly and hit as if you were shooting your field points - accurate and dead on.  Don't stop tinkering until you achieve that result.

What is your arrow length? Maybe you can cut them down a little and stiffen them up.

I should say, I've been shooting for 30 years.  I've tuned arrows for 50-55 lb bows quite a bit.  I understand FOC, GPP, etc.... I've just never tuned arrows for this weight.  I know it depends on lots of variables.  I have several different spine arrows. So, I guess I should say, what point weight would you consider too much for FOC for a 35 lb bow?  I shoot 175 with my heavier bows.  As I set this one up, 175 seems like a bit much, but I don't know.

Quote from: black velvet on September 03, 2025, 10:53:44 AMWhat is your arrow length? Maybe you can cut them down a little and stiffen them up.

The 800s are as short as I can go.  I have some full length Dark Timber 700s.  That's what Big Jim recommended.  But I had some full length 400 spine Gold Tip Kinetics laying around and tried one and it shot fairly well.  I need to shoot some more after i adjust the nock point, etc.. but it may work.

Got it dialed in. Big Jim Dark Timber shaft 700 spine @30.5". Standard insert with 175 grain head. 3x5" fletch.

I would probably start out with a .600 spine shaft and around 150gn of point weight. You stall have shaft length and point weight to play with. I can usually get a pretty stiff arrow to tune well from an ilf rig vs a standard longbow.

Quote from: TaterHill Archer on September 07, 2025, 08:19:36 PMGot it dialed in. Big Jim Dark Timber shaft 700 spine @30.5". Standard insert with 175 grain head. 3x5" fletch.

What you've settled on is about what I use.  I'm shooting a 38# ASL not cut to center.  Big Jim's 700 cut 28 3/4" with a 145 gr point work better than any other combination I've shot.